Well, I've no idea what the ballpark would be for something like this so people who are interested should send me offers (hl2map@nischan.com) along with links to levels they've created I can download to see quality. I'll want it to look like the real building, so there'll be a bunch of textures to make and stuff.
As for map size, umm not sure how to equate it. I've never made a map, so I don't know what units they are measured in. I found a floorplan on the website for the building for the first floor so I made a very crude level layout: http://pics.nischan.com/default.asp?mod ... 915.181317
I'd want basically the area outlined in the jpeg above. A little ways of forest to the north for outdoor fighting/sniping, then the castle itself has 4 levels to it. If someone takes the project, I'll be going back for detailed scale floorplans and site layout.
So if anyone is interested, feel free to email me a bid.